As is known, corrugated cardboard, of the type normally used for boxes or miscellaneous packaging, is produced on special corrugating machines: the sheets of cardboard are fed to the corrugating machine packed tightly between respective cylinder-operated supporting/conveying belts, and are subjected to the combined action of heating assemblies and pressure plates for gluing and shaping the various layers forming the corrugated cardboard.
On known machines, the belts supporting and conveying the cardboard sheets are made of felt, in particular acicular felt, or conventional fabric, which involves various drawbacks. Firstly, felt or conventional fabrics, mainly on account of not always being of even thickness, fail to provide for thin, top-quality finished products, and are therefore unsuitable for producing boxes or packages for select items such as perfume, ornaments, etc., unless the output speed of the machine is greatly reduced. Moreover, felt or conventional fabrics, which must be joined when fitted to the corrugating machine, show marked breaks in continuity at the joints, which further impair the quality of the finished product.
Felt or conventional fabrics are also relatively heavy and therefore difficult to assemble onto the machine; the weight, combined with a high friction coefficient, of such materials increases the energy consumption of the machine; and, finally, not being very permeable, felt or conventional fabrics not only impair dispersion of the steam issuing from the cardboard, but also call for coating the cardboard with a relatively large amount of glue.